RCA 12AX7's (Plate Options)

Plate Length

RCA 12AX7 Collection

Over the years, RCA has offered a variety of different types of 12AX7's (black plates, long grey plates, short grey plates, etc.) and each 12AX7 type has their own strengths, weaknesses, and tonal qualities.

Here are a few rules to remember:

  • Shorter plates are less noisy (on average)
  • Longer plates are tonally more complex i.e. more "depth/fullness" (on average)
  • Reach out to a Fuzz expert if you would like more help determining what tubes are best for you! We can be reached at Support@FuzzAudio.com or by clicking the chat icon in the lower right hand corner of your screen. 

RCA 12AX7 Black Plate

The RCA black plate 12AX7 is 1 of 2 long plate 12AX7 variations manufactured by RCA and is the oldest RCA 12AX7 we offer.

Manufactured roughly between 1950-1959, these tubes would be found stock in classic 1950's Fender Tweed Amplifiers, along with many amplifiers made in the 50's. They are THE best option for restoring American 1950's amps back to former glory or enhancing the sound of a clone!

Two Notable amps that originally used RCA Black Plate 12AX7's:

  • Fender Champ
  • Teletronix LA-2A 

Black plate tubes flourish in smaller amplifiers (typically one speaker) but are excellent for most applications.  They have the least amount of headroom (breakup sooner) amongst the RCA 12AX7 types and come with a HUGE bottom end. They are super warm and are a great option to get rid of some "shrill" in any amplifier.

The RCA 12AX7 black plates' distorted sound is legendary, with lows, mids, and highs all staying more defined than any other tube. If you like fuzz, or play heavy rock and roll- the black plate is for you. 

That being said, black plates can be a tad noisy and if you are trying to avoid noise, these may not be a great choice. Likewise, if you play clean.. these should not be considered as they reduce headroom (breakup sooner) and again, can be noisy. 

Best tubes for one speaker amps hands down. 

RCA 7025 (Short Plate)

In many ways, the RCA 7025 is the opposite of the black plate. It has grey short plates, it is quiet, comes with more headroom, the most recent of RCA tubes made and can be less 3 dimensional in tone. Keep in mind that all RCA 12AX7 variants are tonally exceptional- yet few tubes are as warm as US long plate tubes... 

Rumor is that the 7025 was invented/manufactured to reduce noise in larger guitar amplifiers, and could be found stock in fender amplifiers throughout the 60's. It is the most recent of the RCA tubes manufactured, along with the 12AX7A/ECC83. They are exceptional in Twin Reverbs, any blackface Fender amp, or any application where noise is undesired. 

RCA 12AX7 (Long Grey Plate)

Found stock in Fender, Silvertone, Gibson and so many more classic amplifiers of the late 50's and early 60's, the long grey plate has been heard a million times on all your favorite albums from the 60s and 70s. 

The RCA long grey plate 12AX7 will be less noisy than the black plate but more noisy than the 7025 or 12AX7A (long plates=more noise but better tone). Like the black plate, the long grey plate breaks up sooner and has amazing breakup and clean tone. 

Believe it or not, at Fuzz Audio, we consider this tube the best overall RCA 12AX7 tube if a little noise does not bother you and you like to play clean and dirtay evenly. Compared to the black plate, the long grey plate will have better cleans and less noise. Again, if your amplifier is larger and noise is an issue.. you should consider another type over this one. 

RCA 12AX7A (Short Plate)

Can't wait to get push back from what we are about to say.. but 7025 and 12AX7A are for all into intensive purposes the same.... queue angry mob! 

Although, maybe slightly more noisy, the 12AX7A/ECC83 is a fantastic all around tube that is extremely quiet and great tonally. 

Visit “The Tube Buyer’s Guide” to find the tubes that fit your play style the best!

At Fuzz Audio:

  • All tubes tested for microphonics and are guaranteed to work in audio applications
  • All tubes sold are guaranteed to have strong (to spec) NOS test scores
  • All tubes are tested on a calibrated Hickok 539C (with upgraded digital scales), Maxi-Matcher, or other industry standard tube analyzers
  • Tubes are guaranteed for one year and can be returned within 30 days
  • Preamp tubes matched by gain and mutual conductance (Gm)
  • Power tubes matched by mA and Gm
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